I just discovered a way to build a bankroll with no money at Tux Poker (USA OK)
! Here are the details:
Funstep SNG Coupon Exchange
Click here to exchange $250 play money for Step 1 SnG Coupon
Note: Limit of 10 x Funstep1 Coupon purchases each day. The counter will reset at 00:00 server time.
You will be awarded the coupon FUNSTEP1SNG, this coupon will permit you to enter the Sit'n'Go tournament called "Fun Step 1" in the Tournaments >> Sit N Go >> Hold'em tab.
The winner of the Fun Step 1 tournament will receive a coupon called FUNSTEP2SNG which should be used to gain entry to the "Fun Step 2" tournament.
The winner of the Fun Step 2 tournament will receive a coupon called FUNSTEP3SNG which should be used to gain entry to the "Fun Step 3" tournament.
The winner of the Fun Step 3 tournament will receive $1 real money, to be used in the real money games and tournaments.
Play money is free of course, so conceivably you could do this with a bit of work and some luck!